Complete Question:
Air is made up of gas particles. These particles exert pressure on every object they collide against. This pressure is known as air pressure. Which of the following statements about air pressure is true?
A. The atmosphere's air pressure does not vary;
B. Air pressure decreases as altitude increases;
C. Air pressure increases as altitude increases;
D. Warm air tends to have a higher air pressure than cold air.
Answer:
B.
Step-by-step explanation:
The air pressure depends on the movement of the molecules, so as many molecules presented, as higher is the pressure. When the altitude increases, the top of the atmosphere is being closed, so there's less amount of air. It means there are fewer molecules, so the pressure will decrease.
As higher is the temperature, as more agitated are the molecules, so they are more dispersed, and the pressure is low. So, warm air intends to have a lower air pressure than cold air.